Characterization of Physicochemical Properties of Crude Oil-contaminated Soils In Bodo Oil Field, Nigeria

Abstract

Soil contamination by petroleum hydrocarbons is a major environmental issue in regions like the Niger Delta, Nigeria, where intense oil exploration and spills have significantly degraded soil quality. This study examines the physicochemical properties of soil contaminated with crude oil in the Bodo oil field, aiming to guide sustainable remediation efforts. Soil samples were collected from three sites (SLA, SLB, and SLC) at two depths (0–50 cm and 51–100 cm) and analyzed for pH, electrical conductivity (EC), moisture content, bulk density, total organic carbon (TOC), nitrate, phosphate, and total petroleum hydrocarbons (TPH). Results showed that the soil was highly acidic, with pH values ranging from 2.4 to 3.33, which negatively impacts microbial activity. Electrical conductivity varied between 5.62 and 7.58 mS/cm, indicating high ionic strength due to dissolved salts from hydrocarbon contamination. TOC levels were very high (766.92 ppm), reflecting severe pollution, while nitrate and phosphate levels were low, suggesting limited nutrient availability. TPH concentrations exceeded 3000 ppm in some samples, far surpassing international safety limits. Additionally, volatile organic compounds (VOC) ranged from 37.3 to 79.24 ppm, signaling considerable contamination. These results highlight the urgent need for remediation methods like bioremediation and organic amendments to restore soil health and enable sustainable land management in the affected areas.